MAKING
1) Heat a pan, melt the butter and oil. Put in the onion and garlic, sauté until soft but do not brown it.
2) Pour in the stock, sherry, and add peppers, tomatoes, sugar and parsley.
3) In a bowl, add flour into the melted butter. Whisk. Pour it into the soup. Stir briskly until it boils.
4) Simmer the soup for 5 minutes and take away from heat.
5) You may puree it in a liquidizer for a smooth soup.